Operator platform adjusting mechanism for machines

ABSTRACT

A paving machine is disclosed that includes a tractor, a screed, and an operator platform. The screed is coupled to the tractor and is located behind the tractor. The operator platform is movably coupled to the tractor and has a first position and a second position. In the first position, the operator platform is located at least partially above the screed, and in the second position, the operator platform is located behind the screed.

TECHNICAL FIELD

The present disclosure relates generally to operator platforms in pavingmachines. More specifically, the present disclosure relates to operatorplatforms that are switchable between a first position and a secondposition relative to paving machines.

BACKGROUND

Paving machines are commonly used to lay road forming materials such asasphalt, bitumen, or concrete, on roads, bridges, parking lots, andother similar construction sites. Commonly, paving machines includeapparatuses such as screeds that are applied to smoothen and provideminor compaction to a laid quantity of road forming material, to form amat. During operations, screeds may be extended, retracted, panned, andmanipulated, in a generally two dimensional plane, so as to form adesired mat width. Asphalt paving machines also include operatorplatforms to allow operators to be stationed relative to the screeds andmonitor a quality and pace of the paving operation. In typically smallcommercial pavers of capacity less than 7 tons, such platforms aregenerally positioned behind the screed, rearwardly to the direction ofmovement of the paving machine. As a result, in instances when thepaving machine needs to pave-up to an obstacle, such as a wall, arailing, or a pavement, the operator platform is retracted to a homeposition and is temporarily stacked away until the screed is able toeffectively pave a non-paved surface adjacent to the obstacle.

In conventional operational practice, a retraction of the operatorplatform operator is performed with the platform being manipulated froma generally horizontal plane to a generally vertical plane. As a result,operators stationed on the platform are inevitably required to vacatethe platform, prior to the retraction process, and be posted outside thepaving machine to monitor the paving operation. Such a practice maylimit the operators to control one or more functions of the operatorplatform or of the screed owing to their posting outside. Suchlimitations arise since the control panels positioned locally on thepaving machine become inaccessible to operators from the ground.Furthermore, such a practice is generally time consuming and involvesunwarranted effort. Further, a frequent encounter with obstaclesrequires the operators to vacate the platform on an equivalent number ofoccasions, leading to increased lead time and a generallycounter-productive work schedule.

Japanese Patent Publication JP H07156657 relates to a cab device for acab seat of a construction machine such as an asphalt paver. The cabdevice allows the cab seat to be manipulated so as to keep thevisibility of an operator of the construction machine relativelyunaffected. However, the '657 reference does not provide a solution foroperators stationed on operator platforms of asphalt pavers frommitigating repeated climbing and alighting (or vacating) procedureswhenever, for example, there is a need for the paving machine to pave-upto an obstacle.

Accordingly, the system and method of the present disclosure solves oneor more problems set forth above and other problems in the art.

SUMMARY OF THE INVENTION

Various aspects of the present disclosure illustrate a paving machinethat has a tractor, a screed, and an operator platform. The screed iscoupled to the tractor and located behind the tractor. The operatorplatform is movably coupled to the tractor. The operator platformincludes a first position and a second position. In the first position,the operator platform is located at least partially above the screed. Inthe second position, the operator platform is located behind the screed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an exemplary paving machine incorporated withan operator platform that is positioned in an extended state relative tothe paving machine, in accordance with the concepts of the presentdisclosure;

FIG. 2 is a perspective view of the paving machine of FIG. 1, with theoperator platform being positioned in the extended position, inaccordance with the concepts of the present disclosure; and

FIG. 3 is a perspective view of the paving machine of FIG. 1, with theoperator platform being positioned in a retracted position relative tothe paving machine, in accordance with the concepts of the presentdisclosure.

DETAILED DESCRIPTION

Referring to FIG. 1, there is shown an exemplary paving machine 10,which operates over a non-paved surface 12 and paves the non-pavedsurface 12. The paving machine 10 may be an asphalt paver. To performthe paving operation, the paving machine 10 includes a variety ofcomponents, such as an auger 14, an end gate 16, a screed 18, anoperator platform 20, and a hopper assembly 22. Each of these componentsis suitably connected to a tractor frame 24 of the paving machine 10.The tractor frame 24 may be interchangeably referred to as a tractor 24.The paving machine 10 also provides relative compaction to a roadforming material that is delivered to the non-paved surface 12. The roadforming material may be one of asphalt, bitumen, or concrete, or amixture of these, although other known materials may also becontemplated. A fully formed paved surface may be referred to as a mat26. Further, a machine movement may be executed along a direction, A, asshown. Additionally, the paving machine 10 may include an operator cabportion 28, which in certain implementations forms the same region ashas been defined by the operator platform 20, from where the pavingmachine 10 is controlled and operated. Wherever possible, same referencenumbers may be used throughout the drawings to refer to the same or likeparts.

The auger 14 is adapted to receive and lay the road forming material onthe non-paved surface 12. The auger 14 may embody a screw conveyor,which may include a mechanism that uses a helically shaped screw bladeknown as flighting. A rotation of such a screw conveyor may dump theroad forming material as a stockpile over the non-paved surface 12.

The screed 18 is connected with the tractor 24 and is controllable toevenly spread the dumped stockpile over the non-paved surface 12,depending on a desired width of the mat 20. The screed 18 may provide atleast a minimal compaction to the underlying stockpile to form the mat26. In that way, the screed 18 addresses a preliminary compactionrequirement of the mat 26. A disposal of the stockpile may be such thata flattened, planer layer of the stockpile is substantially uniformlylaid-out on the non-paved surface 12, as the paving machine 10 proceedsin the direction, A.

The end gate 16 may be fixedly engaged along the ends of the screed 18.As the screed 18 assists in the formation of the mat 26, the end gate 16may restrict the unrequited spread of the stockpile beyond the specifiedlimits, and may comply to form a desired mat width. The end gate 16 isgenerally attached to the screed 18 and moves with the screed 18 toprevent undesirable spillage of the road forming material over anadjacent, unpaved surface. Such movement of the end gate 16 with thescreed 18 generally results in the formation of an edged margin betweenthe mat 26 and an adjacent unpaved surface, along an expanse of theassociated roadway.

Referring to FIG. 2, the paving machine 10 with the extended operatorplatform 20 is viewable from a perspective standpoint. The operatorplatform 20 is installed behind the tractor 24, adjacent to the screed18, and rearward to the direction of motion A (FIG. 1) of the pavingmachine 10. The operator platform 20 functions as a walkway that enablesan operator 30 (FIG. 3) to be stationed and observe a progress of thepaving process. While being positioned on the operator platform 20, theoperator 30 (FIG. 3) may also monitor various aspects of the mat 26,such as a leveling, surface finish and width of the mat 26. The operatorplatform 20 includes a proximal rail portion 32, a distal rail portion34, a walkway portion 36, a four-bar linkage assembly 38, and anactuator 40.

The walkway portion 36 is a generally steel base structure, which is aflattened member that is substantially horizontally laid out toeffectuate operator stationing. The walkway portion 36 may bemanufactured from a sheet metal characterized with a sufficient quantityof bends, corners, and stiffeners, to attain a relatively robuststructure that is able to withstand the weight of the operator 30 (FIG.3). While being robust, the operator platform 20 is also considerablylightweight so as to be relatively easily and effortlessly manipulatedto either of an extended or a retracted position (discussed later)relative to the paving machine 10. The walkway portion 36 may beintegrally formed with the proximal rail portion 32 and the distal railportion 34. However, it is also contemplated that the walkway portion 36is formed separately relative to the proximal rail portion 32 and thedistal rail portion 34, and assembled through conventional methods offastening and welding.

The proximal rail portion 32 and the distal rail portion 34 portion aretwo fence (or rail) portions structured and arranged on the operatorplatform 20. It should be noted that the terms “proximal” and “distal,”as used herein, are intended to respectively refer to positions of adevice, component, or a feature, for example, relative to the pavingmachine 10. The proximal rail portion 32 corresponds to the rail portionamong the two fence (or rail) portions of the operator platform 20 thatis closer to the paving machine 10. Conversely, the fence (or rail)portion being relatively farther away from the paving machine 10 isreferred to as the distal rail portion 34. Collectively, the proximalrail portion 32 and the distal rail portion 34 may be referred to asrail portions 32 and 34.

Generally, a disposal of the rail portions 32 and 34 are in manner suchthat the proximal rail portion 32 is substantially closer to the pavingmachine 10, as noted supra. Further, the proximal rail portion 32 issubstantially laterally disposed relative to a length, L, of the pavingmachine 10 (FIG. 1). Similarly, the distal rail portion 34 is disposedsubstantially laterally relative to the length, L, of the paving machine10, but further away from the paving machine 10, than the proximal railportion 32. The disposal of the distal rail portion 34 is nearlyparallel to the proximal rail portion 32, with the walkway portion 36being defined between the proximal rail portion 32 and the distal railportion 34. When viewed from the side, as shown in FIG. 1, the operatorplatform 20 conforms to an almost U-shaped profile, which allowsoperators and personnel to be positioned within the space formed by therail portions 32 and 34 and the walkway portion 36. As shown, similarrail portions are absent on either sides (or the laterally oppositesides) of the operator platform, relative to a length, L, of the pavingmachine 10. Therefore, a generally easy ingress and egress for theoperator 30 (FIG. 3) is assumed.

Referring to FIGS. 2 and 3, the four-bar linkage assembly 38 forms aconnection interface between the paving machine 10 and the operatorplatform 20. The four-bar linkage assembly 38 includes a first four-barlinkage 42 and a second four-bar linkage 44, with each of the firstfour-bar linkage 42 and the second four-bar linkage 44 respectivelyforming individual connection interface portions between the operatorplatform 20 and the either sides (laterally opposed sides) of the pavingmachine 10, as shown. A forthcoming description will be focused towardsthe first four-bar linkage 42 alone. However, it is understood that adescription for the first four-bar linkage 42 is equivalently applicablefor the second four-bar linkage 44, as well.

The first four-bar linkage 42 includes a first shaft member 46 and asecond shaft member 48. The first shaft member 46 is a generallyelongated structural member, which is substantially rigid inconstruction. The first shaft member 46 is pivotally connected with aportion of the tractor 24 of the paving machine 10 at a first end 50 ofthe first shaft member 46. At an opposed second end 52 of the firstshaft member 46, the first shaft member 46 is pivotally connected withthe proximal rail portion 32.

The second shaft member 48 assumes a position below the first shaftmember 46, in a substantially parallel fashion relative to the firstshaft member 46, as shown. As with the first end 50 and the second end52 of the first shaft member 46, the second shaft member 48 includes amachine end 54 and a platform end 56. The machine end 54 correspondsalongside the first end 50 of the first shaft member 46, while theplatform end 56 corresponds alongside the second end 52 of the firstshaft member 46. The second shaft member 48 is also pivotally connectedto the tractor 24 at the machine end 54, while at the platform end 56the second shaft member 48 is pivotally connected to the proximal railportion 32, as well.

Effectively, each of the first shaft member 46 and the second shaftmember 48 are pivotally connected to the tractor 24, while also beingpivotally connected to the proximal rail portion 32. As a result, aparallelogram-linkage is formed between the operator platform 20 and thetractor 24. Which enables the first four-bar linkage 42 to movablyengage the operator platform 20 with the tractor 24. Therefore, arestricted rotatable manipulation is possible between the tractor 24 ofthe paving machine 10 and the operator platform 20. This rotatablemanipulation allows the operator platform 20 to be positioned relativeto the paving machine 10 in at least one of a first position and asecond position. The first position of the operator platform 20corresponds to the deployment of the operator platform 20 relatively andat least partially above the screed 18 (FIG. 3), along an elevation (orheight) of the paving machine 10. In the second position, the operatorplatform 20 is located behind the screed 18 or the tractor 24 (FIG. 2),when viewed along the length, L, of the paving machine 10. In effect,the first position corresponds to a retracted position of the operatorplatform 20, while the second position corresponds to an extendedposition of the operator platform 20 relative to the paving machine 10.

As may be seen by way of the above description, the first four-barlinkage 42 includes a fixed ground link, which is the tractor 24. Sincethe first shaft member 46 and the second shaft member 48 are pivotallyconnected to the tractor 24, the first shaft member 46 and the secondshaft member 48 are grounded links. Lastly, the proximal rail portion 32is a floating link, which is abled for manipulation in relation to thetractor 24. An exemplary manipulation of the first four-bar linkage 42,with pivotal connections at each of the first end 50, the second end 52,the machine end 54, and the platform end 56, is envisioned to beexecuted substantially planarly.

The actuator 40 is adapted to power the movement of the operatorplatform 20 from the first position to the second position. The actuator40 is a linear actuator, which is incorporated into the first four-barlinkage 42. The actuator 40 has a first actuator end 58 and a secondactuator end 60. The first actuator end 58 is connected to the machineend 54 of the second shaft member 48, while the second actuator end 60is connected substantially midway to the first shaft member 46. Althoughthe point of connection described above, it is envisioned that the firstactuator end 58 may be connectable to other portions of the tractor 24or frame of the paving machine 10. In addition, it is possible that theconnection of the second actuator end 60 is away from the midway pointof the first shaft member 46. For example, the second actuator end 60may he connected to either of the second end 52 or the platform end 56respectively of the first shaft member 46 and the second shaft member48. As the actuator 40 is linearly manipulable, a retraction and anextension of the actuator 40 is possible. In turn, such a provisionfacilitates the possibility to tiltably or rotatably lift the firstshaft member 46 generally arcuately (see arrow, B, in FIG. 3) along aheight of the paving machine 10, with the first actuator end 58 forminga rigid reference point from where an associated upward component offorce is applicable.

In an embodiment, the actuator 40 is a screw actuator operable byelectrical activation. However, other actuator types may becontemplated, such as those that are hydraulically or pneumaticallyactivated. Controls for the activation and deactivation of the actuator40 may be provided within or adjacent to the operator cab portion 28 (orthe operator platform 20), which remains accessible to an operatorstationed on the paving machine 10.

Further, the second four-bar linkage 44 assumes a similar role, form,and function, as has been described for the first four-bar linkage 42.Accordingly, it may he assumed that the second four-bar linkage 44 isabled to move planarly as well. This movement is also envisioned along aheight of the paving machine 10. As a result, the first four-bar linkage42 and the second four-bar linkage 44 is manipulable along parallelplanes. However, configuration where a manipulation is affected alongnon-parallel planes may be contemplated as well. Additionally, as withthe connection, form, and function, of the actuator 40 with the firstfour-bar linkage 42, an auxiliary actuator (not shown) is assembled andincorporated with the second four-bar linkage 44, as well.

INDUSTRIAL APPLICABILITY

During road laying operations, it is typically desired to accomplish themat 26 that is characterized by an end-to-end smoothened, planarsurface. However, this is a challenge as a starting point, an end point,or any intermediate point, along an expanse of the associated non-pavedroadway is typically beset with the presence of one or more obstacles.

During operations, the operator 30 within the operator cab portion 28(if present) or from the operator platform 20 may initiate a pavingoperation from or adjacent an obstacle. As it requires to appropriatelylay and provide initial compaction and smoothening to the deliveredstockpile, the operator 30 activates the actuator 40 and effectuates aretraction of the operator platform 20 from a supposed default extendedposition, as shown in FIG. 2, to a retracted position. To this end, theactuator 40 is linearly manipulated and extended upwards along thedirection indicated by the arrow, B (FIG. 3). Simultaneously, thefour-bar linkages 42 and 44 are manipulated along parallel planes. Theoperator 30 may continue with the upward extension of the actuator 40until the operator platform 20 has reached a position where an outermostrearward point on the operator platform 20 is at least in line with anoutermost point on the screed 18. In that way, protruded portions beyondthe screed 18 are drawn back and the screed 18 is rendered free topave-up to an obstacle.

With the four-bar linkages 42 and 44 in place, it is possible for thewalkway portion 36 to remain horizontally aligned even when the operatorplatform 20 is moved to the retracted position (first position) from theextended position (second position). As a result, the operator 30 (FIG.3) positioned on the operator platform 20 may avoid frequent alightingfrom the paving machine 10. Moreover, it is possible that a switchbetween the extended position and the retracted position is executedeven during a movement of the paving machine 10, such as when there isan early detection of an obstacle ahead, during an on-going pavingprocess. Such a provision mitigates the consumption of time, which isconventionally wasted on frequent operator movement relative to thepaving machine 10. Depending upon need, the operator platform 20 may bepositioned infinitely or in multiple positions in-between a fullyretracted position (first position) and a fully extended position(second position), as well.

Advantageously, the retracted position of the operator platform 20 issuited to comply with other situations as well. For example, duringshipping or local transportation, it may be desirable to have theoperator platform 20 in the retracted position and conformed toenclosure requirements of an associated mode of transportation. Further,as the retracted position of the operator platform 20 also correspondsto an elevated walkway portion 36, it is contemplated that the operator30 (FIG. 3) stationed on the operator platform 20 may tap into a line ofsight acquirable in this position, thus freeing the way to view thecontents (road forming materials) of the hopper assembly 22, even whilethe paving machine 10 is in motion and in operation.

It should be understood that the above description is intended forillustrative purposes only and is not intended to limit the scope of thepresent disclosure in any way. Thus, one skilled in the art willappreciate that other aspects of the disclosure may be obtained from astudy of the drawings, the disclosure, and the appended claim.

What is claimed is:
 1. A paving machine comprising: a tractor, a screedcoupled to the tractor and located behind the tractor; and an operatorplatform movably coupled to the tractor and having a first position anda second position; wherein in the first position, the operator platformis located at least partially above the screed, and in the secondposition, the operator platform is located behind the screed.
 2. Thepaving machine of claim 1, further comprising a four-bar linkage thatmovably couples the operator platform to the tractor.
 3. The pavingmachine of claim 2, further comprising an actuator to move the operatorplatform between the first position and the second position.